Staging pleural mesothelioma is important for determining the extent of the disease and guiding treatment decisions. The TNM (Tumor, Node, Metastasis) staging system is commonly used to stage various cancers, including pleural mesothelioma. However, it’s important to note that mesothelioma staging is somewhat different from other cancers because this cancer tends to spread along the pleural lining rather than forming distinct tumors.
The American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC) have collaborated to create a staging system for pleural mesothelioma. The most widely used staging system for pleural mesothelioma is the 8th edition AJCC/UICC TNM staging system.
Here is an overview of the TNM staging system for pleural mesothelioma:
- T-Stage (Tumor Stage):
- TX: Primary tumor cannot be assessed.
- T0: No evidence of primary tumor.
- T1: Tumor involves the parietal pleura on one side.
- T1a: Tumor involves only the ipsilateral parietal pleura.
- T1b: Tumor also involves the ipsilateral diaphragmatic pleura.
- T1c: Tumor also involves the ipsilateral mediastinal pleura.
- T2: Tumor invades the diaphragm and/or lung and/or visceral pleura or the tumor is present in the lung and there is an invasion of the parietal pleura.
- T3: Locally advanced tumor that involves one or more of the following:
- Chest wall (including parietal pericardium)
- Phrenic nerve
- Pericardium (parietal and visceral layers)
- T4: Tumor involves one or more of the following:
- Mediastinal organs (e.g., heart, great vessels, trachea, esophagus, brachial plexus, recurrent laryngeal nerve)
- Transdiaphragmatic extension
- Direct extension to the contralateral pleura
- N-Stage (Lymph Node Involvement):
- NX: Lymph nodes cannot be assessed.
- N0: No regional lymph node involvement.
- N1: Regional lymph node metastasis.
- M-Stage (Distant Metastasis):
- MX: Distant metastasis cannot be assessed.
- M0: No distant metastasis.
- M1: Distant metastasis present.
Once the T, N, and M stages are determined, they are combined to assign an overall stage, ranging from stage I (earliest) to stage IV (most advanced). The stage of pleural mesothelioma helps guide treatment decisions, prognosis, and patient management.
It’s essential to have a detailed evaluation by a medical team experienced in treating mesothelioma to determine the accurate stage of the disease. Treatment options may include surgery, chemotherapy, radiation therapy, and immunotherapy, and the chosen treatment plan often depends on the stage of the disease and the patient’s overall health.